1. Department of Pediatrics, Hospital Dr. Luis Calvo Mackenna, Faculty of Medicine, Universidad de Chile, Santiago, Chile
2. Committee of Infectious Diseases, National Child Programme of Antineoplastic Drugs (PINDA), Santiago, Chile
3. Department of Pediatrics, Hospital San Juan de Dios, Faculty of Medicine, Universidad de Chile, Santiago, Chile
4. Department of Pediatrics, Hospital Dr. Roberto del Río, Faculty of Medicine, Universidad de Chile, Santiago, Chile
5. Department of Pediatrics, Hospital San Borja Arriarán, Faculty of Medicine, Universidad de Chile, Santiago, Chile
6. Department of Pediatrics, Hospital Dr. Exequiel González Cortés, Faculty of Medicine, Universidad de Chile, Santiago, Chile
7. Center for Molecular Studies, Hospital Dr. Luis Calvo Mackenna, Faculty of Medicine, Universidad de Chile, Santiago, Chile